I've only done one FBCT, so I am by no means an expert. But from what I've read, you need at least 50/50 butter/shortening. Why? Because shortening doesn't freeze as hard, and it softens much more quickly when you take it out of the freeer, leaving you less time to work.

You lay a piece of plastic wrap, wax paper or parchment paper over your design. Pipe your outlines and fill in with buttercream, then you freeze it. After it is frozen you can flip it out on your cake and have a picture of what ever you need.

This is a way to get a picture on your cake with out having to free hand.

I have a question, I'm using a crisco and butter recipe..Is this ok for the FBCT? Also what do I use for the outlines? do I use a gel like Wilton's black gel in the tube? I would like to try this today so any help would be great.